More than half of all breast cancers could be avoided by healthy behaviors and chemoprevention, a review of published literature suggested.

Action Points

A review of breast cancer primary prevention strategies estimates that more than half of all breast cancers could be prevented through healthy behaviors and chemoprevention.

A three-marker DNA methylation test of urinary sediments reliably predicted bladder tumor recurrence and was superior to cytology and cystoscopy.

More than half of all breast cancers could be avoided by healthy behaviors and chemoprevention, a review of published literature suggested.

Also included in this OncoBriefs: a study showing lack of evidence to support routine mammography in women older than 74, clinical practice statements that recommend genetic testing and counseling for women with ovarian and endometrial cancer, a potential test for bladder cancer recurrence, and minimally invasive treatment for liver metastases.

The Case for Breast Cancer Prevention

From a worldwide perspective, women with the highest risk for breast cancer have a 13 times greater likelihood of developing the disease than women with the lowest risk.

Variations in screening and reporting practices from nation to nation account for some of the difference, but potentially modifiable factors make up much of the difference, Graham A. Colditz, MD, DrPH, and Kari Bohlke, ScD, of Washington University in St. Louis, asserted in an article published online in CA. A Cancer Journal for Clinicians.

Using published data to support their case, the authors cited modifiable factors that can reduce breast cancer risk for women of all ages. Premenopausal women can reduce their risk by limiting or abstaining from alcohol, maintaining a healthy weight, regular physical activity, prophylactic oophorectomy, chemoprevention with tamoxifen, and following a diet that emphasizes fruits, vegetables, and grains.

Advice about alcohol, weight, and physical activity also apply to postmenopausal women, along with avoidance of combined hormone replacement therapy, and chemoprevention with tamoxifen or raloxifene (Evista).

"Overall, we estimate that more than half of all breast cancers could be prevented through health behaviors and chemoprevention," said Colditz and Bohlke. "This is a substantial reduction in the burden of breast cancer by applying lessons we learned from existing research."

"Even if we fall well short of 50% of cases prevented, we could still prevent thousands of cases of breast cancer each year," they added.

The full report is freely available to the public.

Skip Mammography After 74?

Because they were not included in clinical trials, women 75 or older have no supporting evidence to continue routine mammography, according to an article published online in the Journal of the American Medical Association.

National guidelines encourage women ≥75 to discuss the risks and benefits of mammography with their doctors and then make an individualized decision about whether to undergo screening.

However, landmark clinical trials that established the value of screening mammography did not include women ≥70. Nonetheless, many women in that age group continue routine mammographic screening without discussing the risks and benefits with a clinician.

"People should be informed that everything we do in medicine can have good and bad effects, and that goes for mammography," Louise Walker, MD, of the University of California San Francisco, said in a statement.

Walker and co-author Mara A. Schonberg, MD, of Beth Israel Deaconess Medical Center in Boston, reviewed data from studies conducted during the time period 1990 to 2014 that identified risk factors for breast cancer in women 65 or older and those 75 or older. Because the older group was excluded from the studies, Walker and co-authors could not determine the value of mammography in that group.

Longitudinal studies showed that healthy older women had a reduced risk of breast cancer mortality if they underwent mammographic screening, but regular breast imaging did not prove beneficial for women with significant comorbid medical problems.

Statistical models suggested mammography prevents two cancer deaths among women in their 70s for every 1,000 women screened every other year for 10 years. However, the studies also showed that false-positive results would occur in 200 cases, and 13 women would be treated for cancers that posed no risk.

Genetic Testing for Patients with Ovarian, Endometrial Ca

All women with newly diagnosed epithelial ovarian cancer should consider genetic testing and counseling, even if they do not have a family history of the disease, according to a clinical practice statement from the Society of Gynecologic Oncology (SGO).

Testing for hereditary cancer susceptibility can help determine a patient's risk for other types of cancer and inform other family members about their cancer risk. As justification for the recommendation, SGO officials cited data showing that almost a third of women with hereditary ovarian cancer have no close relatives with cancer, and 35% of newly diagnosed ovarian cancer involves patients older than 60.

"Therefore, all women diagnosed with ovarian, fallopian tube, or peritoneal carcinoma, regardless of age or family history, should receive genetic counselling with consideration of genetic testing," authors of the practice statement advised.

The statement encourages clinicians to offer hereditary risk assessment to all women with ovarian, fallopian tube, and peritoneal cancer.

The SGO supports a two-step evaluation process: a systematic clinical screening, including detailed personal and family medical history, followed by germline or molecular testing.

Despite recommending germline/molecular testing, authors of the practice statement said "a more sensitive strategy is universal molecular tumor testing for either all endometrial cancers or cancers diagnosed at age less than 60, regardless of personal or family cancer history.

Lynch syndrome accounts for 5% or fewer cases of endometrial cancer, but patients with the inherited condition have as much as a 60% lifetime risk for endometrial and colon cancer, according to the SGO statement.

A panel of three biomarkers associated with DNA methylation discriminated between patients with and without cancer recurrence, resulting in area-under-the-curve performance characteristics of 0.90 and 0.95, respectively. The test had a sensitivity of 86% and specificity of 89% in a preliminary evaluation and 80% sensitivity/97% specificity in a validation study.

The test accurately predicted recurrence in 80% of patients, as compared with 35% accuracy for cytology and 15% for cystoscopy. Additionally, the test ruled out recurrence with 74% accuracy.

"This study provides evidence that a marker panel may help minimize the frequency of cystoscopy for patients with a negative score," Gangning Liang, PhD, of the University of Southern California Los Angeles, and co-authors reported. "We suggest that patients with a positive urinary methylation test but no clinical evidence of bladder cancer disease should still be closely monitored because they carry a high risk of recurrence."

Developed from analysis of 368 urine specimens from 90 patients with noninvasive urothelial cancer, initial studies honed six biomarkers down to the three that proved to be most predictive. The concept for the test came from recognition that changes in urinary DNA methylation occur early and reliably persist in bladder carcinogenesis.

Help for Liver Metastases

A minimally invasive procedure to deliver radiation to liver metastases achieved near-100% disease control in a small clinical study.

Radioembolization with yttrium-90 (Y-90) achieved disease control in 98.5% of evaluable patients with chemotherapy-resistant liver metastases from breast cancer. In about a third of cases, tumor shrinkage of 30% or more occurred, as reported at the Society of Interventional Radiology meeting in San Diego.

"Although this is not a cure, Y-90 radioembolization can shrink liver tumors, relieve painful symptoms, improve the quality of life and potentially extend survival," Robert J. Lewandowski, MD, of Northwestern University in Chicago, said in a statement.

"While patient selection is important, the therapy is not limited by tumor size, shape, location, or number, and it can ease the severity of disease in patients who cannot be treated effectively with other approaches."

Lewandowski reported findings from a study of 75 women who had chemoresistant breast cancer metastases to the liver. The lesions were considered untreatable by other methods because they were too large or too numerous. The patients received a total of 98 treatment cycles.

Clinical grade 3 toxicities consisted of abdominal pain in four patients, and nausea, fatigue, and fever in one patient each. Grade 3 laboratory abnormalities consisted of nine cases of elevated transaminases, reduced albumin in three patients, and elevated bilirubin in four patients.

The treatment is not limited to breast cancer metastases but can be used to treat liver metastases from other types of cancer.

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